Controller for motors.



N0- 67|,907- Patented Apr. 9, I901- F. B. DUNCAN.

CONTROLLER FOR MOTORS.

(Application filed July 9, 1900.)

(No Model.)

2 Sheets-Sheet I.

f% Wm No. 67l,907. Patented Apr. 9, |90l F. B. DUNCAN.

CONTROLLER FOR MOTORS.

vApplication filed July 9, 1900.) (No Model.) 2 Shaets-Sheet 2.

mi newefi. 0 1-72 venfar,

MW WWW UNITED STATES PATENT OEEIcE.

FREDERICK B. DUNCAN, OF MADISON,WISCONSIN, ASSIGNOR TO NORTHERN ELECTRICAL MANUFACTURING COMPANY, OF SAME PLACE.

CONTROLLER FOR MOTORS.

SPECIFICATION forming part of Letters Patent No. 671,907, dated April 9, 1901.

Application filed July 9, 1900. Serial No. 22,920. (No model.)

To all whom t nmy co able means is provided for preventing injury Be it known that I, FREDERICK B. DUNCAN, to the motor in case the circuit breaks or the a subject of the Queen of Great Britain, remotor is stopped for any other reason withsiding at Madison, in the county of Dane and out moving the brushes 13 back to their ini 55 State of Wisconsin, have invented a certain tial position. As herein shown, I accomplish new and useful Improvement in Controllers this purpose by providing; a suitable mechanfor Motors, of which the following is a speciism responsive to the variations in the curfication. rent. The movable contacts or brushes in My invention relates to controlling devices the device herein shown engage the outer face 60 I0 for electric motors and the like, and has for of the contacts A in a line substantially parits object to provide a new and improved deallel with the axis about which the controlvice of this description. ling-arm turns, and the arrangement of the My invention is illustrated in the accompacontacts permits a large number of such counying drawings, Whereintacts to be used, thus giving the brushes a 65 Figure l is a diagrammatic view showing a large range of movement. This device is device embodying my invention. Fig. 2 is an used both as a starter and as a controller, and enlarged view showing the resistance-coils hence the mechanism for automatically maand the automatic releasing device. Fig. 3 nipulating the parts must be adapted to work is a section on line 3 3, Fig. 2. when the controlling-arm is in various posi- 7o Like letters refer to like parts throughout tions, and this adaptability must be through the several figures. a comparatively large range. This feature My invention relates particularly to a form presents difficulties not found in the ordinary of controlling device for motors in which the controller; but these difficulties are entirely resistance is automatically manipulated to overcome by the device herein described. 75 protect the motor when the current through Referring now to Figs. 2 and 3, I have illusthe motor is broken or is decreased below a trated one form of mechanism for automatpredetermined point. ically controlling the parts when the circuit Any suitable resistance may be used in convaries in a predetermined manner. In this nection with my invention. I have shown in construction I provide a solenoid D, mount- 80 0 Fig. 2 a particular construction of resistance. ed in any desired manner in proper relation As herein shown, this resistance is made up to the shaft B. This solenoid is provided of a series of coils A, mounted upon a suitwith a core D, having the supporting part able central support A, the coils being di- D This supporting part may be integral vided into suitable sections, which are conwith the core or attached thereto in any de- 85 nected to a series of contacts A arranged in sired manner. Said supporting part D is a circle or the arc of a circle and separated pivot-ally connected with a suitable bracket by suitable insulating-pieces A A controlor support D by means of a pin or the like ling-arm B is associated with the series of con- D This supporting part is provided with a tacts A and is connectedwith a rotatablybinding or holding device, which is adapted o mounted shaft B, which passes through the to bind or hold the shaft B when in a predesupport for the coils. One or more movable termined position. Any desired construction contacts or brushes B are associated with the for this purpose may be used, and, as herein arm B, so as to be moved thereby around the shown, the end of the supporting part D contacts A These brushes and the resistforms an eccentric, as shown in Fig. 3, and 5 ance-coils are suitably connected in circuit is adapted to engage the collar or engaging with the armature of the motor, so that as device E, mounted on the shaft B. The parts the brush is moved around the contacts A are so arranged that when the current the resistance in the circuit is varied. When through the solenoid D ceases or falls below the motor is started, substantially all of the a predetermined strength the core is moved I00 5o resistance is in circuit, the resistance being so as to move the eccentric and release the 1 cut out as the motor gains speed. Some suitshaft B. A suitable retracting device is associated with said shaft so as to move it to its initial position when released. This retracting device consists of the spring 0, one end being connected with the shaft and the other with a fixed part. The solenoid D is connected in series with the shunt-winding F of the motor F. (See Fig. 1.)

-I have described a particular construction embodying my invention; but it is of course evident that the parts may be varied in form, construction, and arrangement and that some of the parts may be omitted and others used with parts not herein shown without departing from the spirit of my invention, and Ido not limit myself to the construction shown.

The use and operation of my invention are as follows: When it is desired to start the motor, the circuit is closed and the controlling-arm B is moved so as to move the movable contacts or brushes along the contacts A The amount of resistance in the armature-circuit is thus varied in the desired manner. When the motor is running, a current is flowing through the coil of the solenoid D, and the e'lfect of this current is to draw the core D of the solenoid inwardly. When this core is drawn inwardly, the parts are moved about the pin D so as to force the eccentric against the collar E. The parts are so arranged that sufficient force is obtained when the core is in its attractive position to bind the shaft and prevent it from rotating. It can, however, be rotated by applying force to the controlling-arm B, but will be held in any desired position when the arm is released. It will thus be seen that the solenoid and associated parts do not aifeet the operators control over the arm B and yet hold the parts in any desired position when the arm B is released. If now the current ceases or falls below a predetermined amount, the attractive force of the solenoid decreases and the core drops away, thus releasing the eccentric from the collar E. The retracting device then moves the controlling-arm back to its initial position, so that when the motor is again started a s'utl'icient amount of resistance will be in the armature-circuit. It will thus be seen that the device acts automatically to protect the motor.

I claim- 1. A controlling device for motors,comprising a variable resistance, a controlling-arm therefor, a solenoid connected in circuit with the motor, a part controlled by said solenoid comprising an eccentric, an engaging part associated with the controllingarm and adapted to be engaged by said eccentric when the current through the coil of the solenoid is normal, so as to hold said arm in any given position, and a retracting device for moving the arm to its initial position when the current through the solenoid falls below a predetermined amount.

2. A controlling device for motors,comprising a variable resistance, a controlling-arm therefor, a solenoid in circuit with the motor, a movably-mounted core therefor provided with an eccentric, an engaging device associated with said controlling-arm normally free to move with relation to said eccentric when no current is passing through the solenoid, the eccentric adapted to be moved so as to be forced against said engaging device when a normal current is passing through the solenoid and hold the arm in any given position, and a retracting device adapted to move said arm to its initial position when the current falls below a predetermined amount.

3. A controlling device for motors, comprising a variable resistance, a controlling-arm therefor, a solenoid adapted to be connected in circuit with the motor, a part controlled by said solenoid and adapted to engage said arm or some part associated therewith, when the solenoid is properly energized, and hold said arm in any desired position.

4. Acontrolling device for motors, comprising a variable resistance, a controlling-arm therefor, an engaging part associated with said controlling-arm, a solenoid responsive to variations in the circuit and provided with a core having attached thereto a part adapted, when the solenoid is properly energized, to engage said engaging part and hold it in any desired position.

5. A controlling device for motors, comprising a variable resistance, a controlling-arm therefor, a solenoid responsive to variations in the current, a lnovably-mounted core therefor provided with an engaging part, an engaging part associated with the controllingarm, the two parts adapted to be brought into ongagement when The core is attracted by the solenoid and adapted to become disengaged when the current through the solenoid falls below a predetermined point.

6. A controlling device for motors, comprising a variable resistance, a controlling-arm therefor, a curved solenoid connected with some part of the motor-circuit, a core therefor having an angular part projecting therefrom, said angular part mounted upon a pivot, so that the core is free to move, an engaging device associated with the controlling-arm and opposed to the angular part projecting from the core, said angular part adapted to engage said engaging device when the core is attracted, so as to hold said arm in any desired position, and a retracting device adapted to move the arm to its initial position when the current through the solenoid falls below a predetermined point.

FREDERICK B. DUNCAN.

Witnesses:

A. P. WARNER, A. J. BUENZLI. 

